package org.seckill.service.impl;

import org.seckill.dao.SeckillDao;
import org.seckill.dao.SuccessKilledDao;
import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.entity.Seckill;
import org.seckill.entity.SuccessKilled;
import org.seckill.enums.SeckillStateEnum;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.seckill.exception.SeckillException;
import org.seckill.service.SeckillService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import java.util.Date;
import java.util.List;

/**
 * Created by 追风少年
 *
 * @email doubihah@foxmail.com
 * @create 2017-05-31 22:02
 **/
@Service
public class SeckillServiceImpl implements SeckillService {

    private Logger logger = LoggerFactory.getLogger(SeckillServiceImpl.class);

    @Autowired
    private SeckillDao seckillDao;
    @Autowired
    private SuccessKilledDao successKilledDao;

    //md5盐值字符串，用于混淆MD5
    private final String slat = "jiodsaj2312o39`1!@@#%%$&&jiodjwqolknc*-qw+q./?sdjizxc120`)(v3d０";

    @Override
    public List<Seckill> getSeckillList() {
        return seckillDao.queryAll(0,5);
    }

    @Override
    public Seckill getById(long seckillId) {
        return seckillDao.queryById(seckillId);
    }

    @Override
    public Exposer exportSeckillUrl(long seckillId) {
        Seckill seckill = seckillDao.queryById(seckillId);
        if(seckill==null){
            return new Exposer(false,seckillId);
        }
        Date startTime = seckill.getStartTime();
        Date endTime = seckill.getEndTime();
        //系统当前时间
        Date nowTime = new Date();
        if(nowTime.getTime() < startTime.getTime()
                ||nowTime.getTime() > endTime.getTime()){
            return new Exposer(false,seckillId,nowTime.getTime(),startTime.getTime(),endTime.getTime());
        }
        //转化特定字符串过程,不可逆
        String md5 = getMD5(seckillId);
        return new Exposer(true,md5,seckillId);
    }

    private String getMD5(long seckillId){
        String base = seckillId + "/" + slat;
        String md5 = DigestUtils.md5DigestAsHex(base.getBytes());
        return md5;
    }

    @Override
    @Transactional
    /**
     * 使用注解控制事务方法的优点:
     *  1：开发团队达成一致约定,明确标注事务方法的编程风格。
     *  2：保证事务方法的执行时间尽可能短,不要穿插其他的网络操作,RPC/HTTP请求 可以剥离到事务方法外部.
     *  3：不是所有的方法都需要事务,如只有一条修改操作,只读操作不需要事务控制.
     */
    public SeckillExecution executeSeckill(long seckillId, String userPhone, String md5) throws SeckillException, RepeatKillException, SeckillCloseException {
        if(md5 == null || !md5.equals(getMD5(seckillId))){
            throw new SeckillException("seckill data rewrite");
        }
        //执行秒杀逻辑：减库存 + 记录秒杀行为
        Date nowTime = new Date();
        try {
            //减库存
            int update = seckillDao.reduceNumber(seckillId,nowTime);
            if(update < 1){
                //没有更新到记录,秒杀结束
                throw new SeckillCloseException("seckill is closed");
            }else{
                //记录购买行为
                int insertCount = successKilledDao.insertSuccessKilled(seckillId,userPhone);
                //唯一：seckillId+userPhone
                if(insertCount < 1){
                    throw new RepeatKillException("seckill repeated");
                }else{
                    //秒杀成功
                    SuccessKilled successKilled = successKilledDao.queryByIdAndUserPhoneWithSeckill(seckillId, userPhone);
                    return new SeckillExecution(seckillId, SeckillStateEnum.SUCCESS, successKilled);
                }
            }//else
        }catch (SeckillCloseException sce){
            throw sce;
        }catch (RepeatKillException rke){
            throw rke;
        }catch (Exception e){
            logger.error(e.getMessage(),e);
            //所有编译期异常 转化为运行期异常
            throw new SeckillException("seckill inner error:" + e.getMessage());
        }
    }
















}
